Joint USAF/NOAA Report of Solar and Geophysical Activity 31 May 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 May 31 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 152 Issued at 2200Z on 31 May 2004
IA. Analysis of Solar Active Regions and Activity from 30/2100Z
to 31/2100Z: Solar activity has been low. Region 618 (S10W83)
produced 5 C-class flares, including a C6.5/Sf at 31/0028 UTC. No
significant development was observed from any of the regions on the
visible disk, and no new regions were numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be very
low to low. Region 618 may still produce C-class flares before
disappearing tomorrow behind the west limb. Region 621 (S15E38) is
capable of C-class flares as well.
IIA. Geophysical Activity Summary 30/2100Z to 31/2100Z:
The geomagnetic field has been quiet to active. Solar wind speed has
slowly increased over the past four days from 350 km/s to about 500
km/s, indicating the possible beginning effects of a coronal hole
high speed solar wind stream.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be unsettled to active for all three days (1-3 June),
with isolated minor storm conditions on 1 and 2 June from the
effects of the geoeffective coronal hole.
III. Event Probabilities 01 Jun-03 Jun
- Class M 20/10/10
- Class X 05/01/01
- Proton 01/01/01
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 31 May 095
- Predicted 01 Jun-03 Jun 100/090/090
- 90 Day Mean 31 May 105
V. Geomagnetic A Indices
- Observed Afr/Ap 30 May 011/013
- Estimated Afr/Ap 31 May 015/015
- Predicted Afr/Ap 01 Jun-03 Jun 015/015-015/015-012/018
VI. Geomagnetic Activity Probabilities 01 Jun-03 Jun
A. Middle Latitudes
- Active 35/35/20
- Minor storm 20/20/10
- Major-severe storm 05/05/01
B. High Latitudes
- Active 40/40/40
- Minor storm 30/25/20
- Major-severe storm 15/15/10
